Fuze for artillery shell



Feb. 2, 1960 H. P. KLAIR 2,923,242

FUZE FOR ARTILLERY SHELL Filed larch a, 1955 2 Sheets-Sheet 1 er WWW 41m Feb. 2, 1960 H. P. KLAIR 2,923,242

' FUZEFOR ARTILLERY sum.

Filed March 8, 1955 2 Sheets-Sheet 2 United States Patent FUZE FOR ARTILLERY SHELL Howard P. Klair, Bloomsburg, Pa.

Application March 8, 1955, Serial No. 492,935

'5 Claims. (Cl. 102-78) The present invention relates to new and useful improvements in fuzes and more particularly to new and useful improvements in fuzes operable to arm a shell or similar article after the shell has been fired and when the acceleration set-back force on the fuze has reached a predetermined range.

The principal object of the invention has been to provide a novel fuze actuated to armed position by acceleration set-back force in a predetermined range and which operates with certainty and precision.

A further object has been to provide a fuze operable to arm shells when the acceleration set-back force thereon has reached a predetermined range, in which there is no need for very close tolerances in the manufacture of the fuze control elements, and wherein these fuze elements do not require a highly polished surface finish.

A still further object of the present invention is to provide a novel mechanical fuze having the features and characteristics set forth which may be manufactured easily and cheaply, and is entirely eflicient and effective in operation and use.

These and other objects of the invention and the various features and details of the operation and construction thereof are hereinafter more fully set forth and described with reference to the accompanying drawings, in which:

Fig. 1 is a front elevational view of a fuze made in accordance with the invention;

Fig. 2 is a side elevational view of the fuze shown in Fig. l in position in a fuze block;

Fig. 3 is a rear elevational view of the fuze;

Fig. 4 is a sectional vew taken on line 4-4, Fig. 2, illustrating the locking plate holding the rotor in the unarmed position;

Fig. 5 is a sectional view taken on line 5-5, Fig. 2, with the rotor moved to the armed position;

Fig. 6 is an enlarged fragmentary view taken on line 6-6 of Fig. 1 illustrating the mounting of the spring member which maintains the locking plate in the latched position;

Fig. 7 is an enlarged fragmentary view illustrating the rotor and locking plate in position immediately after the locking plate is disengaged from the rotor;

Fig. 8 is an enlarged fragmentary view similar to Fig. 7 illustrating the rotor moving to the armed position;

Fig. 9 is a diagrammatic view, illustrating the positions of the latching leaves or plates in latching, disarmed position of the fuze;

Fig. 10 is similar view of the parts after unlatching;

Figs. 11 and 12, 13 and 14, and 15 and 16 are views, respectively, of the three overlapped latching leaves in latched and unlatched positions, and

Fig. 17 is an enlarged view illustrating the latching action of the lowermost leaf.

Referring more specifically to the drawings and particularly Fig. 1 thereof, reference numeral 10 designates generally a fuze assembly mounted in a conventional fuze block 11 which in turn is carried in a shell. A cavity 12 is formed in the fuze block 11 to receive the 2,923,242 Patented Feb. 2, 1960 fuze and maintain the same in position in the fuze block. In additional a relatively small bore 13 is provided longitudinally of the fuze block interconnecting the cavity 12 with one end surface of the fuze block providing communication between the fuze 10 and an explosive charge carried by the shell.

With reference to Figs. 1, 2 and 3, the fuze 10 of the present invention comprises front and rear bearing plates 14 and 15, respectively, maintained in spaced parallel relation by a plurality of spacers 16. A rotor 17 having a trunnion 18 extending outwardly from the forward end thereof is rotatably mounted in the bearing plates 14 and 15 adjacent the rear surface of the rear bearing plate 15. The trunnion 18 extends through openings in the front and rear bearing plates and is loosely supported therein so that the rotor may tilt with respect to the bearing plates as more fully described hereinafter. When the fuze 10 is assembled and positioned interiorly of the fuze block 11 the rotor 17 is positioned inwardly of the cavity 12, as shown in Fig. 2, and has an opening 21' extending transversely therethrough which receives a detonator 22 of conventional construction. The detonator 22 is of the type which may be exploded by passage of current after the completion of an electric circuit thereto.

In accordance with the present invention the rotor 17 is mounted in the bearing plates 14 and 15 for rotary movement between predetermined limit positions. In one limit position the rotor opening 21 and detonator 22 extend generally perpendicular to the fuze block bore 13 and the shell is unarmed and cannot be exploded. In the other limit position the rotor opening 21 extends coaxially 'with the fuze block bore 13 and the end of the detonator is in open communication with the explosive charge carried by the shell. In this limit position the circuit is completed through conventional contact plates engaging the detonator wires and the shell will be exploded by later energization of this circuit, for example by piezometric impact or proximity effect, or other source of energy.

In fuzes of this type the shell is adapted to be armed when the force on the fuze due to the acceleration of the shell reaches a predetermined range. However, the major portion of the acceleration of the shell takes place in the gun barrel, and the fuze must be prevented from moving to an armed position until after the shell has left the gun barrel. In the fuzes of the type to which the present invention pertains this arming of the shell in the gun barrel is prevented by the loose fit of the rotor trunnion 18 in the front and rear bearing plates 14 and 15 since during the initial acceleration of the shell the rotor is displaced transversely of its axis and locked in position by engagement with the walls of the cavity 12 in the fuze block 11.

With reference to Figs. 1 and 4 a pin 25 is secured to the inward surface of the rotor 17 and projects through an arcuate slot 26 formed in the rear bearing plate concentrically with the axis of rotation of the rotor 17. When the fuze is in its unarmed position the pin 25 is positioned adjacent the upper end of the slot as shown in Fig. 4 and when the fuze is in its armed position the pin 25 is moved to the opposite end of the slot as shown in Fig. 8. Means are provided to normally urge the rotor 17 to the armed position. In the illustrated embodiment of the present invention this means consists of a spring 27 having one end thereof wrapped around the end of the rotor trunnion 18 and secured in a slot 28 adjacent the outer end thereof while the other end of the spring is engaged against an upwardly displaced lug 31 formed integrally with the front bearing plate 14 thus tending to twist the rotor in a clockwise direction with respect to Fig. 4.

In accordance with the present invention means are provided to maintain the rotor 17 in its unarmed limit position until a predetermined acceleration set-back force is exerted on the fuze. As shown in Figs. 1 and 4, this is accomplished by means of a locking plate 32 mounted intermediate the front and rear bearing plates for pivotal movement about a pin 33 extending therebetween. The locking plate 32 has a hook portion 34 at one side thereof which engages the rotor pin 25 and maintains the rotor in its unarmed position. A spring 35 has portions coiled about a pair of pins 36 and 37 and free ends in engagement with grooves in end surfaces of latching plates or leaves 38 and 39 which overlie the latching or locking plate 32 and lock it in position as discussed hereinafter. The hook portion 34 of the locking plate 32 engages about a substantial portion of the periphery of the rotor pin 25, for example as shown in Figs. 1 and 17. Thus, force exerted on the hook by the rotor pin tends to elongate the latching member 32 and this is resisted by pivot pin 33, so that this force creates a. longitudinal pull on the pivot pin instead of turning the latching member about this pin as an axis.

An important feature of the present invention is the provision of means for insuring that the rotor pin 25 and the locking plate 32 may become disengaged when acceleration set-back conditions are established to permit the rotor to be moved to the armed position. The fuze is mounted in a shell so that the force on the fuze elements due to the acceleration of the shell will act in the upward direction with respect to Fig. l, and the latching plates 39, 38 and 32 are released in that order to release the rotor pin 25 and permit movement of the rotor to armed position. This sequence results from the features illustrated in Figs. 9-17 of the drawing.

The patching plates 38 and 39 are of known construction and operate in accordance with known principles, and the novel features of this invention relate to modification of the plate 32 for coaction therewith to insure against jamming of the mechanism in disarmed position.

The latching plates 32 and 39 are mounted for pivotal movement about pin 33, while plate 38 pivots about pin 42. Each of plates 32 and 39 is provided with an enlarged circular opening 43 and 44, respectively, surrounding pivot pin 42. and plate 38 has a similar opening 45 surrounding pivot pin 33. The inner circumferences of openings 43-45 limit the extent of pivotal movement of plates 32, 39 and 38 about their respective pivot pins.

When all of the plates are in the latched posit on they will occupy the latching relationship illustrated in Fig. 9. The progressive interlatching of the successive underlying plates is achieved through pins or studs 46 and 47 standing upwardly, as illustrated, from peripheral extensions on these plates and abutting peripheral portions of overlying plates 38 and 39, respectively. So long as the parts are maintained in this position by spring 35, the rotor pin 25 will remain locked against movement from disarmed to armed position.

When the shell is fired, it moves and accelerates in a direction which is downward with respect to the drawing illustration, and this creates an acceleration set-back force on plate 39 causing it to pivot against the pressure from spring 35 from the position of Fig. to the position of Fig. 16. The peripheral portion blocking upward movement of pin 47 is thus moved upwardly, permitting plate 38 to pivot from the position of Fig. 13 to the position of Fig. 14. This in turn releases pin 46 from the blocking peripheral portion of plate 38, permitting plate 32 in turn to be moved about pivot 33 from the position of Fig. 11 to the position of Fig. 12. The movement of the successive plates as thus achieved results from the set-back force due to acceleration of the shell, since the preponderance of of each plate is on the side of its pivot pin creating movement in the desired direction.

The movement of the three latching or locking plates, as discussed above, results in total in changes in position of these respective plates from those illustrated in Fig. 9 to those illustrated in Fig. 10, with the result that the pin 25 is released from its bearing in the hook 34, and will move within slot 26 in clockwise direction to the opposite end of this slot 26 as the rotor moves from disarmed to armed position. As noted above, however, this movement will occur only after the changes in acceleration occur upon the shell leaving the barrel of the gun.

Insofar as the general sequence of operation discussed above is concerned, it is not a part of the present invention. Fuzes designed for this sequence of operations in the prior art, however, have created difliculty by jamming, and analysis of this difliculty has shown that it resulted from binding of the undersurface of the plate 38 abutting the pin 46, with the consequence that plate 38 was restrained by such binding from undergoing the movement from the position of Fig. 13 to the position of Fig. 14, with the consequence that plate 38 remained in latching engagement through pin 46 with plate 32, preventing this plate 32 from releasing the rotor pin 25 and the rotor for movement to armed position as explained hereinabove.

The jamming occurring between pin 46 and the abutting lower surface of plate 38 has resulted from force directly applied by pin 25 against the surface of the plate 38 which it abuts, tending to rotate this plate about the pivot pin 33. This has been a consequence of provision, on the surface of the plate 32 latching pin 25 in position, of a cam extending diagonally downwardly across slot 26. In the present invention, instead of providing such a diagonally extending blocking surface, there is provided the hook 34, and this extends to a substantial extent around the circumference of the pin 25, as discussed above, with the consequence that rotation of pin 25 in its groove tends to exert a pulling effect against the pivot pin 33 in an effort to elongate the latching plate or member 32. Since it is impossible for the plate to stretch substantially or to move in the direction of the pull, the pin '25 is blocked in its effort to cause plate 32 to pivot around pin 33 to a position in which the stud or pin 46 at the other end of the plate is jammed against the overlying edge of plate 38. Thus, by the simple expedient of providing a hook which resists the longitudinal component of movement discussed above, the jamming effect of spring 27 as exerted upon pin 25 to plate 32 and stud 46 is eliminated, and each of the parts is free to move in the sequence discussed above in unlatching of the successive plates to release the fuze rotor for movement to armed position.

While the invention has been discussed above in relation to a single specific embodiment, it will be evident to those skilled in the art that it may be refined and modified in various ways without departing from its basic concept, and I therefore wish it to be understood that the patent protection hereby afforded is not to be limited in scope except by the following claims.

I claim:

1. In a shell fuze, the combination comprising a fuze body having a recess therein to receive a rotor, a rotor mounted in said recess and movable from a position in which said rotor is in fuze disarming condition to a position in which said fuze is armed, means for exerting a steady force for rotating said rotor from disarmed to armed position, a latching plate pivotally mounted in position for latching said rotor against movement from disarmed to armed position, said latching plate having a hooked outer end spaced from the pivotal mounting thereof, said hooked outer end being in hooking engagement about a substantial circumferential portion of the periphery of a stud secured to said rotor, said hooking engagement extending around said stud at least to a point on a line extending between the center of said pivotal mounting and said stud, said hooked end being in a position to prevent pivotal movement of said latching plate in response to exertion of said steady force, and said latching plate having a preponderance of mass located to exert a pivotal force to cause release of said hook from said stud, upon development of a predetermined acceleration set-back force thereupon, and a second latching plate overlying the hooked latching plate, said hook latching plate having a stud projecting from a face thereof into latching engagement with a surface of said second latching plate, said second latching plate being also pivotally mounted and being yieldingly biassed into latching position and having its mass distributed to cause pivotal movement to releasing position, upon development of a predetermined acceleration set-back force thereupon.

2. A shell fuze as defined in claim 1, in which a third latching plate overlies said second latching plate in the same latching relation as that of said second latching plate to said first latching plate.

3. A shell fuze as defined in claim 2, in which said first and third latching plates are mounted for rotation about a common pivotal axis, and in which said second latching plate is mounted about an axis spaced therefrom.

4. A shell fuze as defined in claim 3, in which said axes are upstanding studs and each of said plates is provided with an enlarged hole which receives the stud axially mounting other of said plates to limit the pivotal movement thereof.

5. In a shell fuze, the combination comprising a fuze body having a recess therein to receive a rotor, a rotor mounted in said recess and movable from a position in which said rotor is in fuze disarming condition to a position in which said fuze is armed, means for exerting a steady force for rotating said rotor from disarmed to armed position, and a pair of overlapped latching plates pivotally mounted about spaced axes in position for latching said rotor against movement from disarmed to armed position, the lowermost latching plate having a hooked outer end spaced from said mounting axis thereof, said hooked outer end being in hooking engagement about a substantial circumferential portion of theperiphery of a stud secured to said rotor, said hooking engagement extending around said stud at least to a point on a line extending between the center of the mounting axis of said lowermost latching plate and said stud, said hooked end being in a position to prevent pivotal movement of said latching plate in response to exertion of said steady force, and said lowermost latching plate having a preponderance of mass located to exert a pivotal force to cause relase of said hook from said stud, upon development of a predetermined acceleration set-back thereon and the overlying latching plate having a peripheral surface abutted by a stud projecting from a face of said underlying latching plate when the plates are in latching position, and means for yieldingly holding said overlying latching plate in latching position, said overlying latching plate also having a preponderance of mass located to exert a pivotal force to cause release thereof from engagement with the upstanding stud of said first latching plate upon development of a predetermined acceleration set-back force thereupon.

References Cited in the file of this patent UNITED STATES PATENTS 

